Patch to add RGBA support and disable decorations.

Hi, I wrote this patch to that adds the following optional features that I missed from gnome/xfce terminals:

USE_RGBA: Sets RGBA colormap and calls the corresponding vte methods to enable it. Requires composite manager, and probably a recent VTE version that adds vte_terminal_set_opacity(). The amount of opacity is controlled with BACKGROUND_SATURATION, because there is a weird relation between both features. Also, when USE_RGBA is set, vte_terminal_set_background_transparent() is #if'd out, because it sets fake transparency.
HIDE_DECORATIONS: Almost oneliner, calls gtk_window_set_decorated() to tell the window manager to skip drawing decorations (borders, title bar, etc) in the evilvte window.

The diff is here, againist evilvte 0.3.5:

Can you please get this applied in evilvte? Thanks

-dx (at dxzone.com.ar)